HORTON, J. Wright Jr1, MCNAMARA, Daniel E.
2, SHAH, Anjana K.
3, GILMER, Amy K.
4, CARTER, Aina M.
5, BURTON, William C.
6, HARRISON, Richard W.
1, CARTER, Mark W.
1, HERRMANN, Robert B.
7, and SNYDER, Stephen L.
1, (1) U.S. Geological Survey, 926A National Center, Reston, VA 20192, whorton@usgs.gov, (2) US Geological Survey, 966 Denver Federal Center, Denver, CO 80225, (3) U.S. Geological Survey, Denver Federal Center, POB 25046, MS 964, Denver, CO 80225, (4) Division of Geology and Mineral Resources, Virginia Department of Mines, Minerals and Energy, 900 Natural Resources Drive, Suite 500, Charlottesville, VA 22903, (5) Louisa, VA 23093, (6) U.S. Geological Survey, MS 926A, Reston, VA 20192, (7) Earth and Atmospheric Sciences, St. Louis University, 203 O'Neil Hall, 3642 Lindell Blvd, St. Louis, MO 63108